powerpc/kdump: Use ppc_save_regs() in crash_setup_regs()

The patch replaces internal registers dump implementation with
ppc_save_regs(). From now on PPC64 and PPC32 are using the same
code for crash_setup_regs().

NOTE: The old regs dump implementation was capturing SP (r1) directly
as is, so you could see crash_kexec() function on top of the back-trace.
But ppc_save_regs() goes up one stack frame, so you'll not see it
anymore, at the top-level you'll see who actually triggered the crash
dump instead.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/kexec.h

@@ -48,63 +48,8 @@ static inline void crash_setup_regs(struct pt_regs *newregs,
 {
 	if (oldregs)
 		memcpy(newregs, oldregs, sizeof(*newregs));
-#ifdef __powerpc64__
-	else {
-		/* FIXME Merge this with xmon_save_regs ?? */
-		unsigned long tmp1, tmp2;
-		__asm__ __volatile__ (
-			"std    0,0(%2)\n"
-			"std    1,8(%2)\n"
-			"std    2,16(%2)\n"
-			"std    3,24(%2)\n"
-			"std    4,32(%2)\n"
-			"std    5,40(%2)\n"
-			"std    6,48(%2)\n"
-			"std    7,56(%2)\n"
-			"std    8,64(%2)\n"
-			"std    9,72(%2)\n"
-			"std    10,80(%2)\n"
-			"std    11,88(%2)\n"
-			"std    12,96(%2)\n"
-			"std    13,104(%2)\n"
-			"std    14,112(%2)\n"
-			"std    15,120(%2)\n"
-			"std    16,128(%2)\n"
-			"std    17,136(%2)\n"
-			"std    18,144(%2)\n"
-			"std    19,152(%2)\n"
-			"std    20,160(%2)\n"
-			"std    21,168(%2)\n"
-			"std    22,176(%2)\n"
-			"std    23,184(%2)\n"
-			"std    24,192(%2)\n"
-			"std    25,200(%2)\n"
-			"std    26,208(%2)\n"
-			"std    27,216(%2)\n"
-			"std    28,224(%2)\n"
-			"std    29,232(%2)\n"
-			"std    30,240(%2)\n"
-			"std    31,248(%2)\n"
-			"mfmsr  %0\n"
-			"std    %0, 264(%2)\n"
-			"mfctr  %0\n"
-			"std    %0, 280(%2)\n"
-			"mflr   %0\n"
-			"std    %0, 288(%2)\n"
-			"bl     1f\n"
-		"1:     mflr   %1\n"
-			"std    %1, 256(%2)\n"
-			"mtlr   %0\n"
-			"mfxer  %0\n"
-			"std    %0, 296(%2)\n"
-			: "=&r" (tmp1), "=&r" (tmp2)
-			: "b" (newregs)
-			: "memory");
-	}
-#else
 	else
 		ppc_save_regs(newregs);
-#endif /* __powerpc64__ */
 }
 
 extern void kexec_smp_wait(void);	/* get and clear naca physid, wait for